Some people prefer to date during weekends. Married men tend to date girfriends during weekdays so as not to raise suspicions.
But what is the ideal day for dating?
I'd say Saturdays are always best. You don't have to go to work the following day, you can stay out drinking and partying longer.
On the other hand, many likeminded people do the same on Saturdays, so most proper places are overbooked, noisy and can be unpleasant.
Going at a restaurant which is packed full is not my ideal scenario for dating. The buzz around you makes dating unexpected and can destroy the magic (if any).
Those who can afford it, booking at a luxury hotel and not having to care is best, but if you prefer your place you need to prepare and follow my earlier advice.
Also women tend to enjoy the fun at a "buzzy" nightclub, or a bar. But during weekdays this can be a lot of fun in a very pleasant environment.